net/ipv4/fib_hash.c

   1 /*
   2  * INET         An implementation of the TCP/IP protocol suite for the LINUX
   3  *              operating system.  INET is implemented using the  BSD Socket
   4  *              interface as the means of communication with the user level.
   5  *
   6  *              IPv4 FIB: lookup engine and maintenance routines.
   7  *
   8  * Authors:     Alexey Kuznetsov, <[email protected]>
   9  *
  10  *              This program is free software; you can redistribute it and/or
  11  *              modify it under the terms of the GNU General Public License
  12  *              as published by the Free Software Foundation; either version
  13  *              2 of the License, or (at your option) any later version.
  14  */
  15
  16 #include <asm/uaccess.h>
  17 #include <asm/system.h>
  18 #include <linux/bitops.h>
  19 #include <linux/types.h>
  20 #include <linux/kernel.h>
  21 #include <linux/mm.h>
  22 #include <linux/string.h>
  23 #include <linux/socket.h>
  24 #include <linux/sockios.h>
  25 #include <linux/errno.h>
  26 #include <linux/in.h>
  27 #include <linux/inet.h>
  28 #include <linux/inetdevice.h>
  29 #include <linux/netdevice.h>
  30 #include <linux/if_arp.h>
  31 #include <linux/proc_fs.h>
  32 #include <linux/skbuff.h>
  33 #include <linux/netlink.h>
  34 #include <linux/init.h>
  35
  36 #include <net/net_namespace.h>
  37 #include <net/ip.h>
  38 #include <net/protocol.h>
  39 #include <net/route.h>
  40 #include <net/tcp.h>
  41 #include <net/sock.h>
  42 #include <net/ip_fib.h>
  43
  44 #include "fib_lookup.h"
  45
  46 static struct kmem_cache *fn_hash_kmem __read_mostly;
  47 static struct kmem_cache *fn_alias_kmem __read_mostly;
  48
  49 struct fib_node {
  50         struct hlist_node       fn_hash;
  51         struct list_head        fn_alias;
  52         __be32                  fn_key;
  53         struct fib_alias        fn_embedded_alias;
  54 };
  55
  56 struct fn_zone {
  57         struct fn_zone          *fz_next;       /* Next not empty zone  */
  58         struct hlist_head       *fz_hash;       /* Hash table pointer   */
  59         int                     fz_nent;        /* Number of entries    */
  60
  61         int                     fz_divisor;     /* Hash divisor         */
  62         u32                     fz_hashmask;    /* (fz_divisor - 1)     */
  63 #define FZ_HASHMASK(fz)         ((fz)->fz_hashmask)
  64
  65         int                     fz_order;       /* Zone order           */
  66         __be32                  fz_mask;
  67 #define FZ_MASK(fz)             ((fz)->fz_mask)
  68 };
  69
  70 /* NOTE. On fast computers evaluation of fz_hashmask and fz_mask
  71  * can be cheaper than memory lookup, so that FZ_* macros are used.
  72  */
  73
  74 struct fn_hash {
  75         struct fn_zone  *fn_zones[33];
  76         struct fn_zone  *fn_zone_list;
  77 };
  78
  79 static inline u32 fn_hash(__be32 key, struct fn_zone *fz)
  80 {
  81         u32 h = ntohl(key)>>(32 - fz->fz_order);
  82         h ^= (h>>20);
  83         h ^= (h>>10);
  84         h ^= (h>>5);
  85         h &= FZ_HASHMASK(fz);
  86         return h;
  87 }
  88
  89 static inline __be32 fz_key(__be32 dst, struct fn_zone *fz)
  90 {
  91         return dst & FZ_MASK(fz);
  92 }
  93
  94 static DEFINE_RWLOCK(fib_hash_lock);
  95 static unsigned int fib_hash_genid;
  96
  97 #define FZ_MAX_DIVISOR ((PAGE_SIZE<<MAX_ORDER) / sizeof(struct hlist_head))
  98
  99 static struct hlist_head *fz_hash_alloc(int divisor)
 100 {
 101         unsigned long size = divisor * sizeof(struct hlist_head);
 102
 103         if (size <= PAGE_SIZE) {
 104                 return kzalloc(size, GFP_KERNEL);
 105         } else {
 106                 return (struct hlist_head *)
 107                         __get_free_pages(GFP_KERNEL | __GFP_ZERO, get_order(size));
 108         }
 109 }
 110
 111 /* The fib hash lock must be held when this is called. */
 112 static inline void fn_rebuild_zone(struct fn_zone *fz,
 113                                    struct hlist_head *old_ht,
 114                                    int old_divisor)
 115 {
 116         int i;
 117
 118         for (i = 0; i < old_divisor; i++) {
 119                 struct hlist_node *node, *n;
 120                 struct fib_node *f;
 121
 122                 hlist_for_each_entry_safe(f, node, n, &old_ht[i], fn_hash) {
 123                         struct hlist_head *new_head;
 124
 125                         hlist_del(&f->fn_hash);
 126
 127                         new_head = &fz->fz_hash[fn_hash(f->fn_key, fz)];
 128                         hlist_add_head(&f->fn_hash, new_head);
 129                 }
 130         }
 131 }
 132
 133 static void fz_hash_free(struct hlist_head *hash, int divisor)
 134 {
 135         unsigned long size = divisor * sizeof(struct hlist_head);
 136
 137         if (size <= PAGE_SIZE)
 138                 kfree(hash);
 139         else
 140                 free_pages((unsigned long)hash, get_order(size));
 141 }
 142
 143 static void fn_rehash_zone(struct fn_zone *fz)
 144 {
 145         struct hlist_head *ht, *old_ht;
 146         int old_divisor, new_divisor;
 147         u32 new_hashmask;
 148
 149         old_divisor = fz->fz_divisor;
 150
 151         switch (old_divisor) {
 152         case 16:
 153                 new_divisor = 256;
 154                 break;
 155         case 256:
 156                 new_divisor = 1024;
 157                 break;
 158         default:
 159                 if ((old_divisor << 1) > FZ_MAX_DIVISOR) {
 160                         printk(KERN_CRIT "route.c: bad divisor %d!\n", old_divisor);
 161                         return;
 162                 }
 163                 new_divisor = (old_divisor << 1);
 164                 break;
 165         }
 166
 167         new_hashmask = (new_divisor - 1);
 168
 169 #if RT_CACHE_DEBUG >= 2
 170         printk(KERN_DEBUG "fn_rehash_zone: hash for zone %d grows from %d\n",
 171                fz->fz_order, old_divisor);
 172 #endif
 173
 174         ht = fz_hash_alloc(new_divisor);
 175
 176         if (ht) {
 177                 write_lock_bh(&fib_hash_lock);
 178                 old_ht = fz->fz_hash;
 179                 fz->fz_hash = ht;
 180                 fz->fz_hashmask = new_hashmask;
 181                 fz->fz_divisor = new_divisor;
 182                 fn_rebuild_zone(fz, old_ht, old_divisor);
 183                 fib_hash_genid++;
 184                 write_unlock_bh(&fib_hash_lock);
 185
 186                 fz_hash_free(old_ht, old_divisor);
 187         }
 188 }
 189
 190 static inline void fn_free_node(struct fib_node * f)
 191 {
 192         kmem_cache_free(fn_hash_kmem, f);
 193 }
 194
 195 static inline void fn_free_alias(struct fib_alias *fa, struct fib_node *f)
 196 {
 197         fib_release_info(fa->fa_info);
 198         if (fa == &f->fn_embedded_alias)
 199                 fa->fa_info = NULL;
 200         else
 201                 kmem_cache_free(fn_alias_kmem, fa);
 202 }
 203
 204 static struct fn_zone *
 205 fn_new_zone(struct fn_hash *table, int z)
 206 {
 207         int i;
 208         struct fn_zone *fz = kzalloc(sizeof(struct fn_zone), GFP_KERNEL);
 209         if (!fz)
 210                 return NULL;
 211
 212         if (z) {
 213                 fz->fz_divisor = 16;
 214         } else {
 215                 fz->fz_divisor = 1;
 216         }
 217         fz->fz_hashmask = (fz->fz_divisor - 1);
 218         fz->fz_hash = fz_hash_alloc(fz->fz_divisor);
 219         if (!fz->fz_hash) {
 220                 kfree(fz);
 221                 return NULL;
 222         }
 223         fz->fz_order = z;
 224         fz->fz_mask = inet_make_mask(z);
 225
 226         /* Find the first not empty zone with more specific mask */
 227         for (i=z+1; i<=32; i++)
 228                 if (table->fn_zones[i])
 229                         break;
 230         write_lock_bh(&fib_hash_lock);
 231         if (i>32) {
 232                 /* No more specific masks, we are the first. */
 233                 fz->fz_next = table->fn_zone_list;
 234                 table->fn_zone_list = fz;
 235         } else {
 236                 fz->fz_next = table->fn_zones[i]->fz_next;
 237                 table->fn_zones[i]->fz_next = fz;
 238         }
 239         table->fn_zones[z] = fz;
 240         fib_hash_genid++;
 241         write_unlock_bh(&fib_hash_lock);
 242         return fz;
 243 }
 244
 245 int fib_table_lookup(struct fib_table *tb,
 246                      const struct flowi *flp, struct fib_result *res)
 247 {
 248         int err;
 249         struct fn_zone *fz;
 250         struct fn_hash *t = (struct fn_hash *)tb->tb_data;
 251
 252         read_lock(&fib_hash_lock);
 253         for (fz = t->fn_zone_list; fz; fz = fz->fz_next) {
 254                 struct hlist_head *head;
 255                 struct hlist_node *node;
 256                 struct fib_node *f;
 257                 __be32 k = fz_key(flp->fl4_dst, fz);
 258
 259                 head = &fz->fz_hash[fn_hash(k, fz)];
 260                 hlist_for_each_entry(f, node, head, fn_hash) {
 261                         if (f->fn_key != k)
 262                                 continue;
 263
 264                         err = fib_semantic_match(&f->fn_alias,
 265                                                  flp, res,
 266                                                  fz->fz_order);
 267                         if (err <= 0)
 268                                 goto out;
 269                 }
 270         }
 271         err = 1;
 272 out:
 273         read_unlock(&fib_hash_lock);
 274         return err;
 275 }
 276
 277 void fib_table_select_default(struct fib_table *tb,
 278                               const struct flowi *flp, struct fib_result *res)
 279 {
 280         int order, last_idx;
 281         struct hlist_node *node;
 282         struct fib_node *f;
 283         struct fib_info *fi = NULL;
 284         struct fib_info *last_resort;
 285         struct fn_hash *t = (struct fn_hash *)tb->tb_data;
 286         struct fn_zone *fz = t->fn_zones[0];
 287
 288         if (fz == NULL)
 289                 return;
 290
 291         last_idx = -1;
 292         last_resort = NULL;
 293         order = -1;
 294
 295         read_lock(&fib_hash_lock);
 296         hlist_for_each_entry(f, node, &fz->fz_hash[0], fn_hash) {
 297                 struct fib_alias *fa;
 298
 299                 list_for_each_entry(fa, &f->fn_alias, fa_list) {
 300                         struct fib_info *next_fi = fa->fa_info;
 301
 302                         if (fa->fa_scope != res->scope ||
 303                             fa->fa_type != RTN_UNICAST)
 304                                 continue;
 305
 306                         if (next_fi->fib_priority > res->fi->fib_priority)
 307                                 break;
 308                         if (!next_fi->fib_nh[0].nh_gw ||
 309                             next_fi->fib_nh[0].nh_scope != RT_SCOPE_LINK)
 310                                 continue;
 311                         fa->fa_state |= FA_S_ACCESSED;
 312
 313                         if (fi == NULL) {
 314                                 if (next_fi != res->fi)
 315                                         break;
 316                         } else if (!fib_detect_death(fi, order, &last_resort,
 317                                                 &last_idx, tb->tb_default)) {
 318                                 fib_result_assign(res, fi);
 319                                 tb->tb_default = order;
 320                                 goto out;
 321                         }
 322                         fi = next_fi;
 323                         order++;
 324                 }
 325         }
 326
 327         if (order <= 0 || fi == NULL) {
 328                 tb->tb_default = -1;
 329                 goto out;
 330         }
 331
 332         if (!fib_detect_death(fi, order, &last_resort, &last_idx,
 333                                 tb->tb_default)) {
 334                 fib_result_assign(res, fi);
 335                 tb->tb_default = order;
 336                 goto out;
 337         }
 338
 339         if (last_idx >= 0)
 340                 fib_result_assign(res, last_resort);
 341         tb->tb_default = last_idx;
 342 out:
 343         read_unlock(&fib_hash_lock);
 344 }
 345
 346 /* Insert node F to FZ. */
 347 static inline void fib_insert_node(struct fn_zone *fz, struct fib_node *f)
 348 {
 349         struct hlist_head *head = &fz->fz_hash[fn_hash(f->fn_key, fz)];
 350
 351         hlist_add_head(&f->fn_hash, head);
 352 }
 353
 354 /* Return the node in FZ matching KEY. */
 355 static struct fib_node *fib_find_node(struct fn_zone *fz, __be32 key)
 356 {
 357         struct hlist_head *head = &fz->fz_hash[fn_hash(key, fz)];
 358         struct hlist_node *node;
 359         struct fib_node *f;
 360
 361         hlist_for_each_entry(f, node, head, fn_hash) {
 362                 if (f->fn_key == key)
 363                         return f;
 364         }
 365
 366         return NULL;
 367 }
 368
 369 int fib_table_insert(struct fib_table *tb, struct fib_config *cfg)
 370 {
 371         struct fn_hash *table = (struct fn_hash *) tb->tb_data;
 372         struct fib_node *new_f = NULL;
 373         struct fib_node *f;
 374         struct fib_alias *fa, *new_fa;
 375         struct fn_zone *fz;
 376         struct fib_info *fi;
 377         u8 tos = cfg->fc_tos;
 378         __be32 key;
 379         int err;
 380
 381         if (cfg->fc_dst_len > 32)
 382                 return -EINVAL;
 383
 384         fz = table->fn_zones[cfg->fc_dst_len];
 385         if (!fz && !(fz = fn_new_zone(table, cfg->fc_dst_len)))
 386                 return -ENOBUFS;
 387
 388         key = 0;
 389         if (cfg->fc_dst) {
 390                 if (cfg->fc_dst & ~FZ_MASK(fz))
 391                         return -EINVAL;
 392                 key = fz_key(cfg->fc_dst, fz);
 393         }
 394
 395         fi = fib_create_info(cfg);
 396         if (IS_ERR(fi))
 397                 return PTR_ERR(fi);
 398
 399         if (fz->fz_nent > (fz->fz_divisor<<1) &&
 400             fz->fz_divisor < FZ_MAX_DIVISOR &&
 401             (cfg->fc_dst_len == 32 ||
 402              (1 << cfg->fc_dst_len) > fz->fz_divisor))
 403                 fn_rehash_zone(fz);
 404
 405         f = fib_find_node(fz, key);
 406
 407         if (!f)
 408                 fa = NULL;
 409         else
 410                 fa = fib_find_alias(&f->fn_alias, tos, fi->fib_priority);
 411
 412         /* Now fa, if non-NULL, points to the first fib alias
 413          * with the same keys [prefix,tos,priority], if such key already
 414          * exists or to the node before which we will insert new one.
 415          *
 416          * If fa is NULL, we will need to allocate a new one and
 417          * insert to the head of f.
 418          *
 419          * If f is NULL, no fib node matched the destination key
 420          * and we need to allocate a new one of those as well.
 421          */
 422
 423         if (fa && fa->fa_tos == tos &&
 424             fa->fa_info->fib_priority == fi->fib_priority) {
 425                 struct fib_alias *fa_first, *fa_match;
 426
 427                 err = -EEXIST;
 428                 if (cfg->fc_nlflags & NLM_F_EXCL)
 429                         goto out;
 430
 431                 /* We have 2 goals:
 432                  * 1. Find exact match for type, scope, fib_info to avoid
 433                  * duplicate routes
 434                  * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it
 435                  */
 436                 fa_match = NULL;
 437                 fa_first = fa;
 438                 fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
 439                 list_for_each_entry_continue(fa, &f->fn_alias, fa_list) {
 440                         if (fa->fa_tos != tos)
 441                                 break;
 442                         if (fa->fa_info->fib_priority != fi->fib_priority)
 443                                 break;
 444                         if (fa->fa_type == cfg->fc_type &&
 445                             fa->fa_scope == cfg->fc_scope &&
 446                             fa->fa_info == fi) {
 447                                 fa_match = fa;
 448                                 break;
 449                         }
 450                 }
 451
 452                 if (cfg->fc_nlflags & NLM_F_REPLACE) {
 453                         struct fib_info *fi_drop;
 454                         u8 state;
 455
 456                         fa = fa_first;
 457                         if (fa_match) {
 458                                 if (fa == fa_match)
 459                                         err = 0;
 460                                 goto out;
 461                         }
 462                         write_lock_bh(&fib_hash_lock);
 463                         fi_drop = fa->fa_info;
 464                         fa->fa_info = fi;
 465                         fa->fa_type = cfg->fc_type;
 466                         fa->fa_scope = cfg->fc_scope;
 467                         state = fa->fa_state;
 468                         fa->fa_state &= ~FA_S_ACCESSED;
 469                         fib_hash_genid++;
 470                         write_unlock_bh(&fib_hash_lock);
 471
 472                         fib_release_info(fi_drop);
 473                         if (state & FA_S_ACCESSED)
 474                                 rt_cache_flush(cfg->fc_nlinfo.nl_net, -1);
 475                         rtmsg_fib(RTM_NEWROUTE, key, fa, cfg->fc_dst_len, tb->tb_id,
 476                                   &cfg->fc_nlinfo, NLM_F_REPLACE);
 477                         return 0;
 478                 }
 479
 480                 /* Error if we find a perfect match which
 481                  * uses the same scope, type, and nexthop
 482                  * information.
 483                  */
 484                 if (fa_match)
 485                         goto out;
 486
 487                 if (!(cfg->fc_nlflags & NLM_F_APPEND))
 488                         fa = fa_first;
 489         }
 490
 491         err = -ENOENT;
 492         if (!(cfg->fc_nlflags & NLM_F_CREATE))
 493                 goto out;
 494
 495         err = -ENOBUFS;
 496
 497         if (!f) {
 498                 new_f = kmem_cache_zalloc(fn_hash_kmem, GFP_KERNEL);
 499                 if (new_f == NULL)
 500                         goto out;
 501
 502                 INIT_HLIST_NODE(&new_f->fn_hash);
 503                 INIT_LIST_HEAD(&new_f->fn_alias);
 504                 new_f->fn_key = key;
 505                 f = new_f;
 506         }
 507
 508         new_fa = &f->fn_embedded_alias;
 509         if (new_fa->fa_info != NULL) {
 510                 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
 511                 if (new_fa == NULL)
 512                         goto out;
 513         }
 514         new_fa->fa_info = fi;
 515         new_fa->fa_tos = tos;
 516         new_fa->fa_type = cfg->fc_type;
 517         new_fa->fa_scope = cfg->fc_scope;
 518         new_fa->fa_state = 0;
 519
 520         /*
 521          * Insert new entry to the list.
 522          */
 523
 524         write_lock_bh(&fib_hash_lock);
 525         if (new_f)
 526                 fib_insert_node(fz, new_f);
 527         list_add_tail(&new_fa->fa_list,
 528                  (fa ? &fa->fa_list : &f->fn_alias));
 529         fib_hash_genid++;
 530         write_unlock_bh(&fib_hash_lock);
 531
 532         if (new_f)
 533                 fz->fz_nent++;
 534         rt_cache_flush(cfg->fc_nlinfo.nl_net, -1);
 535
 536         rtmsg_fib(RTM_NEWROUTE, key, new_fa, cfg->fc_dst_len, tb->tb_id,
 537                   &cfg->fc_nlinfo, 0);
 538         return 0;
 539
 540 out:
 541         if (new_f)
 542                 kmem_cache_free(fn_hash_kmem, new_f);
 543         fib_release_info(fi);
 544         return err;
 545 }
 546
 547 int fib_table_delete(struct fib_table *tb, struct fib_config *cfg)
 548 {
 549         struct fn_hash *table = (struct fn_hash *)tb->tb_data;
 550         struct fib_node *f;
 551         struct fib_alias *fa, *fa_to_delete;
 552         struct fn_zone *fz;
 553         __be32 key;
 554
 555         if (cfg->fc_dst_len > 32)
 556                 return -EINVAL;
 557
 558         if ((fz  = table->fn_zones[cfg->fc_dst_len]) == NULL)
 559                 return -ESRCH;
 560
 561         key = 0;
 562         if (cfg->fc_dst) {
 563                 if (cfg->fc_dst & ~FZ_MASK(fz))
 564                         return -EINVAL;
 565                 key = fz_key(cfg->fc_dst, fz);
 566         }
 567
 568         f = fib_find_node(fz, key);
 569
 570         if (!f)
 571                 fa = NULL;
 572         else
 573                 fa = fib_find_alias(&f->fn_alias, cfg->fc_tos, 0);
 574         if (!fa)
 575                 return -ESRCH;
 576
 577         fa_to_delete = NULL;
 578         fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
 579         list_for_each_entry_continue(fa, &f->fn_alias, fa_list) {
 580                 struct fib_info *fi = fa->fa_info;
 581
 582                 if (fa->fa_tos != cfg->fc_tos)
 583                         break;
 584
 585                 if ((!cfg->fc_type ||
 586                      fa->fa_type == cfg->fc_type) &&
 587                     (cfg->fc_scope == RT_SCOPE_NOWHERE ||
 588                      fa->fa_scope == cfg->fc_scope) &&
 589                     (!cfg->fc_protocol ||
 590                      fi->fib_protocol == cfg->fc_protocol) &&
 591                     fib_nh_match(cfg, fi) == 0) {
 592                         fa_to_delete = fa;
 593                         break;
 594                 }
 595         }
 596
 597         if (fa_to_delete) {
 598                 int kill_fn;
 599
 600                 fa = fa_to_delete;
 601                 rtmsg_fib(RTM_DELROUTE, key, fa, cfg->fc_dst_len,
 602                           tb->tb_id, &cfg->fc_nlinfo, 0);
 603
 604                 kill_fn = 0;
 605                 write_lock_bh(&fib_hash_lock);
 606                 list_del(&fa->fa_list);
 607                 if (list_empty(&f->fn_alias)) {
 608                         hlist_del(&f->fn_hash);
 609                         kill_fn = 1;
 610                 }
 611                 fib_hash_genid++;
 612                 write_unlock_bh(&fib_hash_lock);
 613
 614                 if (fa->fa_state & FA_S_ACCESSED)
 615                         rt_cache_flush(cfg->fc_nlinfo.nl_net, -1);
 616                 fn_free_alias(fa, f);
 617                 if (kill_fn) {
 618                         fn_free_node(f);
 619                         fz->fz_nent--;
 620                 }
 621
 622                 return 0;
 623         }
 624         return -ESRCH;
 625 }
 626
 627 static int fn_flush_list(struct fn_zone *fz, int idx)
 628 {
 629         struct hlist_head *head = &fz->fz_hash[idx];
 630         struct hlist_node *node, *n;
 631         struct fib_node *f;
 632         int found = 0;
 633
 634         hlist_for_each_entry_safe(f, node, n, head, fn_hash) {
 635                 struct fib_alias *fa, *fa_node;
 636                 int kill_f;
 637
 638                 kill_f = 0;
 639                 list_for_each_entry_safe(fa, fa_node, &f->fn_alias, fa_list) {
 640                         struct fib_info *fi = fa->fa_info;
 641
 642                         if (fi && (fi->fib_flags&RTNH_F_DEAD)) {
 643                                 write_lock_bh(&fib_hash_lock);
 644                                 list_del(&fa->fa_list);
 645                                 if (list_empty(&f->fn_alias)) {
 646                                         hlist_del(&f->fn_hash);
 647                                         kill_f = 1;
 648                                 }
 649                                 fib_hash_genid++;
 650                                 write_unlock_bh(&fib_hash_lock);
 651
 652                                 fn_free_alias(fa, f);
 653                                 found++;
 654                         }
 655                 }
 656                 if (kill_f) {
 657                         fn_free_node(f);
 658                         fz->fz_nent--;
 659                 }
 660         }
 661         return found;
 662 }
 663
 664 int fib_table_flush(struct fib_table *tb)
 665 {
 666         struct fn_hash *table = (struct fn_hash *) tb->tb_data;
 667         struct fn_zone *fz;
 668         int found = 0;
 669
 670         for (fz = table->fn_zone_list; fz; fz = fz->fz_next) {
 671                 int i;
 672
 673                 for (i = fz->fz_divisor - 1; i >= 0; i--)
 674                         found += fn_flush_list(fz, i);
 675         }
 676         return found;
 677 }
 678
 679
 680 static inline int
 681 fn_hash_dump_bucket(struct sk_buff *skb, struct netlink_callback *cb,
 682                      struct fib_table *tb,
 683                      struct fn_zone *fz,
 684                      struct hlist_head *head)
 685 {
 686         struct hlist_node *node;
 687         struct fib_node *f;
 688         int i, s_i;
 689
 690         s_i = cb->args[4];
 691         i = 0;
 692         hlist_for_each_entry(f, node, head, fn_hash) {
 693                 struct fib_alias *fa;
 694
 695                 list_for_each_entry(fa, &f->fn_alias, fa_list) {
 696                         if (i < s_i)
 697                                 goto next;
 698
 699                         if (fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
 700                                           cb->nlh->nlmsg_seq,
 701                                           RTM_NEWROUTE,
 702                                           tb->tb_id,
 703                                           fa->fa_type,
 704                                           fa->fa_scope,
 705                                           f->fn_key,
 706                                           fz->fz_order,
 707                                           fa->fa_tos,
 708                                           fa->fa_info,
 709                                           NLM_F_MULTI) < 0) {
 710                                 cb->args[4] = i;
 711                                 return -1;
 712                         }
 713                 next:
 714                         i++;
 715                 }
 716         }
 717         cb->args[4] = i;
 718         return skb->len;
 719 }
 720
 721 static inline int
 722 fn_hash_dump_zone(struct sk_buff *skb, struct netlink_callback *cb,
 723                    struct fib_table *tb,
 724                    struct fn_zone *fz)
 725 {
 726         int h, s_h;
 727
 728         if (fz->fz_hash == NULL)
 729                 return skb->len;
 730         s_h = cb->args[3];
 731         for (h = s_h; h < fz->fz_divisor; h++) {
 732                 if (hlist_empty(&fz->fz_hash[h]))
 733                         continue;
 734                 if (fn_hash_dump_bucket(skb, cb, tb, fz, &fz->fz_hash[h]) < 0) {
 735                         cb->args[3] = h;
 736                         return -1;
 737                 }
 738                 memset(&cb->args[4], 0,
 739                        sizeof(cb->args) - 4*sizeof(cb->args[0]));
 740         }
 741         cb->args[3] = h;
 742         return skb->len;
 743 }
 744
 745 int fib_table_dump(struct fib_table *tb, struct sk_buff *skb,
 746                    struct netlink_callback *cb)
 747 {
 748         int m, s_m;
 749         struct fn_zone *fz;
 750         struct fn_hash *table = (struct fn_hash *)tb->tb_data;
 751
 752         s_m = cb->args[2];
 753         read_lock(&fib_hash_lock);
 754         for (fz = table->fn_zone_list, m=0; fz; fz = fz->fz_next, m++) {
 755                 if (m < s_m) continue;
 756                 if (fn_hash_dump_zone(skb, cb, tb, fz) < 0) {
 757                         cb->args[2] = m;
 758                         read_unlock(&fib_hash_lock);
 759                         return -1;
 760                 }
 761                 memset(&cb->args[3], 0,
 762                        sizeof(cb->args) - 3*sizeof(cb->args[0]));
 763         }
 764         read_unlock(&fib_hash_lock);
 765         cb->args[2] = m;
 766         return skb->len;
 767 }
 768
 769 void __init fib_hash_init(void)
 770 {
 771         fn_hash_kmem = kmem_cache_create("ip_fib_hash", sizeof(struct fib_node),
 772                                          0, SLAB_PANIC, NULL);
 773
 774         fn_alias_kmem = kmem_cache_create("ip_fib_alias", sizeof(struct fib_alias),
 775                                           0, SLAB_PANIC, NULL);
 776
 777 }
 778
 779 struct fib_table *fib_hash_table(u32 id)
 780 {
 781         struct fib_table *tb;
 782
 783         tb = kmalloc(sizeof(struct fib_table) + sizeof(struct fn_hash),
 784                      GFP_KERNEL);
 785         if (tb == NULL)
 786                 return NULL;
 787
 788         tb->tb_id = id;
 789         tb->tb_default = -1;
 790
 791         memset(tb->tb_data, 0, sizeof(struct fn_hash));
 792         return tb;
 793 }
 794
 795 /* ------------------------------------------------------------------------ */
 796 #ifdef CONFIG_PROC_FS
 797
 798 struct fib_iter_state {
 799         struct seq_net_private p;
 800         struct fn_zone  *zone;
 801         int             bucket;
 802         struct hlist_head *hash_head;
 803         struct fib_node *fn;
 804         struct fib_alias *fa;
 805         loff_t pos;
 806         unsigned int genid;
 807         int valid;
 808 };
 809
 810 static struct fib_alias *fib_get_first(struct seq_file *seq)
 811 {
 812         struct fib_iter_state *iter = seq->private;
 813         struct fib_table *main_table;
 814         struct fn_hash *table;
 815
 816         main_table = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN);
 817         table = (struct fn_hash *)main_table->tb_data;
 818
 819         iter->bucket    = 0;
 820         iter->hash_head = NULL;
 821         iter->fn        = NULL;
 822         iter->fa        = NULL;
 823         iter->pos       = 0;
 824         iter->genid     = fib_hash_genid;
 825         iter->valid     = 1;
 826
 827         for (iter->zone = table->fn_zone_list; iter->zone;
 828              iter->zone = iter->zone->fz_next) {
 829                 int maxslot;
 830
 831                 if (!iter->zone->fz_nent)
 832                         continue;
 833
 834                 iter->hash_head = iter->zone->fz_hash;
 835                 maxslot = iter->zone->fz_divisor;
 836
 837                 for (iter->bucket = 0; iter->bucket < maxslot;
 838                      ++iter->bucket, ++iter->hash_head) {
 839                         struct hlist_node *node;
 840                         struct fib_node *fn;
 841
 842                         hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
 843                                 struct fib_alias *fa;
 844
 845                                 list_for_each_entry(fa, &fn->fn_alias, fa_list) {
 846                                         iter->fn = fn;
 847                                         iter->fa = fa;
 848                                         goto out;
 849                                 }
 850                         }
 851                 }
 852         }
 853 out:
 854         return iter->fa;
 855 }
 856
 857 static struct fib_alias *fib_get_next(struct seq_file *seq)
 858 {
 859         struct fib_iter_state *iter = seq->private;
 860         struct fib_node *fn;
 861         struct fib_alias *fa;
 862
 863         /* Advance FA, if any. */
 864         fn = iter->fn;
 865         fa = iter->fa;
 866         if (fa) {
 867                 BUG_ON(!fn);
 868                 list_for_each_entry_continue(fa, &fn->fn_alias, fa_list) {
 869                         iter->fa = fa;
 870                         goto out;
 871                 }
 872         }
 873
 874         fa = iter->fa = NULL;
 875
 876         /* Advance FN. */
 877         if (fn) {
 878                 struct hlist_node *node = &fn->fn_hash;
 879                 hlist_for_each_entry_continue(fn, node, fn_hash) {
 880                         iter->fn = fn;
 881
 882                         list_for_each_entry(fa, &fn->fn_alias, fa_list) {
 883                                 iter->fa = fa;
 884                                 goto out;
 885                         }
 886                 }
 887         }
 888
 889         fn = iter->fn = NULL;
 890
 891         /* Advance hash chain. */
 892         if (!iter->zone)
 893                 goto out;
 894
 895         for (;;) {
 896                 struct hlist_node *node;
 897                 int maxslot;
 898
 899                 maxslot = iter->zone->fz_divisor;
 900
 901                 while (++iter->bucket < maxslot) {
 902                         iter->hash_head++;
 903
 904                         hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
 905                                 list_for_each_entry(fa, &fn->fn_alias, fa_list) {
 906                                         iter->fn = fn;
 907                                         iter->fa = fa;
 908                                         goto out;
 909                                 }
 910                         }
 911                 }
 912
 913                 iter->zone = iter->zone->fz_next;
 914
 915                 if (!iter->zone)
 916                         goto out;
 917
 918                 iter->bucket = 0;
 919                 iter->hash_head = iter->zone->fz_hash;
 920
 921                 hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
 922                         list_for_each_entry(fa, &fn->fn_alias, fa_list) {
 923                                 iter->fn = fn;
 924                                 iter->fa = fa;
 925                                 goto out;
 926                         }
 927                 }
 928         }
 929 out:
 930         iter->pos++;
 931         return fa;
 932 }
 933
 934 static struct fib_alias *fib_get_idx(struct seq_file *seq, loff_t pos)
 935 {
 936         struct fib_iter_state *iter = seq->private;
 937         struct fib_alias *fa;
 938
 939         if (iter->valid && pos >= iter->pos && iter->genid == fib_hash_genid) {
 940                 fa   = iter->fa;
 941                 pos -= iter->pos;
 942         } else
 943                 fa = fib_get_first(seq);
 944
 945         if (fa)
 946                 while (pos && (fa = fib_get_next(seq)))
 947                         --pos;
 948         return pos ? NULL : fa;
 949 }
 950
 951 static void *fib_seq_start(struct seq_file *seq, loff_t *pos)
 952         __acquires(fib_hash_lock)
 953 {
 954         void *v = NULL;
 955
 956         read_lock(&fib_hash_lock);
 957         if (fib_get_table(seq_file_net(seq), RT_TABLE_MAIN))
 958                 v = *pos ? fib_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 959         return v;
 960 }
 961
 962 static void *fib_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 963 {
 964         ++*pos;
 965         return v == SEQ_START_TOKEN ? fib_get_first(seq) : fib_get_next(seq);
 966 }
 967
 968 static void fib_seq_stop(struct seq_file *seq, void *v)
 969         __releases(fib_hash_lock)
 970 {
 971         read_unlock(&fib_hash_lock);
 972 }
 973
 974 static unsigned fib_flag_trans(int type, __be32 mask, struct fib_info *fi)
 975 {
 976         static const unsigned type2flags[RTN_MAX + 1] = {
 977                 [7] = RTF_REJECT, [8] = RTF_REJECT,
 978         };
 979         unsigned flags = type2flags[type];
 980
 981         if (fi && fi->fib_nh->nh_gw)
 982                 flags |= RTF_GATEWAY;
 983         if (mask == htonl(0xFFFFFFFF))
 984                 flags |= RTF_HOST;
 985         flags |= RTF_UP;
 986         return flags;
 987 }
 988
 989 /*
 990  *      This outputs /proc/net/route.
 991  *
 992  *      It always works in backward compatibility mode.
 993  *      The format of the file is not supposed to be changed.
 994  */
 995 static int fib_seq_show(struct seq_file *seq, void *v)
 996 {
 997         struct fib_iter_state *iter;
 998         int len;
 999         __be32 prefix, mask;
1000         unsigned flags;
1001         struct fib_node *f;
1002         struct fib_alias *fa;
1003         struct fib_info *fi;
1004
1005         if (v == SEQ_START_TOKEN) {
1006                 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
1007                            "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
1008                            "\tWindow\tIRTT");
1009                 goto out;
1010         }
1011
1012         iter    = seq->private;
1013         f       = iter->fn;
1014         fa      = iter->fa;
1015         fi      = fa->fa_info;
1016         prefix  = f->fn_key;
1017         mask    = FZ_MASK(iter->zone);
1018         flags   = fib_flag_trans(fa->fa_type, mask, fi);
1019         if (fi)
1020                 seq_printf(seq,
1021                          "%s\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u%n",
1022                          fi->fib_dev ? fi->fib_dev->name : "*", prefix,
1023                          fi->fib_nh->nh_gw, flags, 0, 0, fi->fib_priority,
1024                          mask, (fi->fib_advmss ? fi->fib_advmss + 40 : 0),
1025                          fi->fib_window,
1026                          fi->fib_rtt >> 3, &len);
1027         else
1028                 seq_printf(seq,
1029                          "*\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u%n",
1030                          prefix, 0, flags, 0, 0, 0, mask, 0, 0, 0, &len);
1031
1032         seq_printf(seq, "%*s\n", 127 - len, "");
1033 out:
1034         return 0;
1035 }
1036
1037 static const struct seq_operations fib_seq_ops = {
1038         .start  = fib_seq_start,
1039         .next   = fib_seq_next,
1040         .stop   = fib_seq_stop,
1041         .show   = fib_seq_show,
1042 };
1043
1044 static int fib_seq_open(struct inode *inode, struct file *file)
1045 {
1046         return seq_open_net(inode, file, &fib_seq_ops,
1047                             sizeof(struct fib_iter_state));
1048 }
1049
1050 static const struct file_operations fib_seq_fops = {
1051         .owner          = THIS_MODULE,
1052         .open           = fib_seq_open,
1053         .read           = seq_read,
1054         .llseek         = seq_lseek,
1055         .release        = seq_release_net,
1056 };
1057
1058 int __net_init fib_proc_init(struct net *net)
1059 {
1060         if (!proc_net_fops_create(net, "route", S_IRUGO, &fib_seq_fops))
1061                 return -ENOMEM;
1062         return 0;
1063 }
1064
1065 void __net_exit fib_proc_exit(struct net *net)
1066 {
1067         proc_net_remove(net, "route");
1068 }
1069 #endif /* CONFIG_PROC_FS */